Python自动化之sqlalchemy复合外键

复合外键用法

metadata = MetaData(engine)
                classedu = Table('classedu', metadata,
                # Column('qq', BigInteger, primary_key=True),
                Column('classname', VARCHAR(20), primary_key=True),
                Column('coursename', VARCHAR(20),primary_key=True))


##这是一个复合外键
student = Table('student', metadata,
             Column('qq', BigInteger, primary_key=True),
             Column('classname', VARCHAR(20)),
             Column('coursename', VARCHAR(20)),
             ForeignKeyConstraint(['classname', 'coursename'], ['classedu.classname', 'classedu.coursename'])
             )

metadata.create_all(engine)


Base = declarative_base()


book_m2m_author = Table('book_m2m_author', Base.metadata,
                        Column('book_id',Integer,ForeignKey('books.id')),
                        Column('author_id',Integer,ForeignKey('authors.id')),
                        )

class Book(Base):
    __tablename__ = 'books'
    id = Column(Integer,primary_key=True)
    name = Column(String(64))
    pub_date = Column(DATE)
    authors = relationship('Author',secondary=book_m2m_author,backref='books')

参考如下
http://docs.sqlalchemy.org/en/rel_1_1/core/constraints.html